Merge pull request #1633 from danforthcenter/zeeuqsze-grayscale-colab

Update grayscale_tutorial.md

Author: nfahlgren

docs/tutorials/grayscale_tutorial.md

@@ -1,9 +1,9 @@
 ## Tutorial: Single plant Grayscale image workflow
 
+Check out our interactive tutorial! Learn how to extract pixel intensity information from a grayscale plant image of tobacco.
+
 [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/danforthcenter/plantcv-tutorial-grayscale/HEAD?labpath=index.ipynb)
-<a target="_blank" href="https://colab.research.google.com/github/danforthcenter/plantcv-tutorial-grayscale.git">
-  <img src="https://colab.research.google.com/assets/colab-badge.svg" alt="Open In Colab"/>
-</a>
+[![Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/danforthcenter/plantcv-tutorial-grayscale/blob/main/index-Colab.ipynb)
 [![Static Badge](https://img.shields.io/badge/Open%20on%20GitHub-black?logo=github)](https://github.com/danforthcenter/plantcv-tutorial-grayscale.git)
 
 <iframe src="https://nbviewer.jupyter.org/github/danforthcenter/plantcv-tutorial-grayscale/blob/main/index.ipynb" width="100%" height="1500px"></iframe>